code: def test_powerset_method():
      # EmptySet
      A = FiniteSet()
      pset = A.powerset()
      assert len(pset) == 1
      assert pset == FiniteSet(S.EmptySet)
  
      # FiniteSets
      A = FiniteSet(1, 2)
      pset = A.powerset()
      assert len(pset) == 2 ** len(A)
      assert pset == FiniteSet(
          FiniteSet(), FiniteSet(1), FiniteSet(2), A
      )
      # Not finite sets
      A = Interval(0, 1)
      assert A.powerset() == PowerSet(A)
  
file_path: sympy/sympy/sets/tests/test_powerset.py
imports: from sympy.core.expr import unchanged
  from sympy.core.singleton import S
  from sympy.core.symbol import Symbol
  from sympy.sets.contains import Contains
  from sympy.sets.fancysets import Interval
  from sympy.sets.powerset import PowerSet
  from sympy.sets.sets import FiniteSet
  from sympy.testing.pytest import raises, XFAIL
label_desc: Use image node_id 9 for calling a global function with example usage: test_powerset_method() without return types